A:电磁打点计时器使用的是10V以下的直流电源,电火花计时器使用的是220V交流电源
B:在测量物体速度时,先让物体运动,后接通电源
C:电磁打点计时器和电火花计时器打点时间间隔都是0.02S
D:纸带上打的点越密,说明物体运动的越慢
连线题。
①Would you like some chicken?____ A. No. I like swimming.
②Do you like snakes?____ B. Yes, it is.
③Do you like skipping? ____ C. No, thanks. I like salad.
④Touch this. Is it soft?____ D. No, I don't. I like giraffe.